Gregor Townsend was keen to sign the scrum-half in 2012 when Grayson played for the NSW Waratahs.
Grayson eventually joined Edinburgh and had now moved to Glasgow on a two-year deal, and the New Zealand-born player is delighted to finally get his Warriors career up and running.
Grayson told glasgowwarriors.org: "I spoke a lot to Gregor a few years ago about coming and at the time it didn’t quite feel like the right time as I had a few things I still wanted to do back home.
“From those discussions I kept an eye on Glasgow and now I’m here it just feels right.”
"I was hugely excited and happy for the guys when I watched the final. I felt like the club really deserved to win that championship.
“They’ve been building over the years and really earned it. It’s a very exciting time to be joining the club.
“I rocked up on the first day for pre-season training and wouldn’t usually have such a spring in my step but joining a winning club was really exciting for me.
“I’ve kept a close eye on Glasgow over the years and what stood out for me is the way they play the game.
“They encourage their players to express themselves and it’s an exciting style of rugby to watch.
“Coming from the Southern Hemisphere, it’s similar to my mindset. I’ll need to work really hard on my fitness to keep the tempo high for the team.”